Nope, all spells are detirmed by ancient knowledge alone. If you have fireball there is no need to get lightning or ice lance, they all do roughly the same damage for the same mana. It's a waste of LPs to go with more than one of those spells, as no creatures have very high resistances to anything.

I'll give you a few advice on spells:
- Get Summon Demon as soon as possible(205AK), and use him as a tank when you need it. He can take an incredible amount of pain before dying.
- Healing and Light are needed, basic spells I get on all characters(30AK is easy to get for any character just by reading books). That way I can avoid those annoying torches and reduce the number of healing potions I need.
- Only get 1 low mana cost damage spell(either lightning, ice lance or fireball). They all do the same basically.
- Get one area effect spell, such as the upgraded version of Lightning, Rain of Fire or Thunderstorm. Useful in certain situations, but no need to get more than one of them.

All in all, if you don't want to waste ANY points at all, get Fireball, Rain of Fire, Healing, Light and Summon Demon. Personally I like to have a few more just for fun, but they're not actually needed. If this is your first mage game, I suggest getting some other spells as well just to try it out, but maybe save before trying them as some seem cool but are utterly useless, hehe.